The invention relates to centrifugal blood processing systems and apparatus.
Certain therapies transfuse large volumes of blood components. For example, some patients undergoing chemotherapy require the transfusion of large numbers of platelets on a routine basis. Manual blood bag systems simply are not an efficient way to collect these large numbers of platelets from individual donors.
On line blood separation systems are today used to collect large numbers of platelets to meet this demand. On line systems perform the separation steps necessary to separate concentration of platelets from whole blood in a sequential process with the donor present. On line systems establish a flow of whole blood from the donor, separate out the desired platelets from the flow, and return the remaining red blood cells and plasma to the donor, all in a sequential flow loop.
Large volumes of whole blood (for example, 2.0 liters) can be processed using an on line system. Due to the large processing volumes, large yields of concentrated platelets (for example, 4xc3x971011 platelets suspended in 200 ml of fluid) can be collected.
Nevertheless, a need still exists to further improve systems and methods for collecting cellular-rich concentrates, like red blood cells, from blood components, in a way that lends itself to use in high volume, on line blood collection environments, where higher yields of critically needed cellular blood components like platelets and red blood cells can be realized.
The invention provides blood processing systems and methods that separate blood drawn from a donor through a blood processing circuit to perform a desired blood collection procedure. During the procedure, a volume of the targeted blood component is collected. The systems and methods derive an estimated effect of the procedure upon the donor. The systems and methods present the estimated effect to an operator.
According to one aspect of the invention, the estimated effect is expressed in terms of a net blood fluid volume loss. In one embodiment, the estimated effect takes into account blood loss due to the volume of targeted blood component collected and a residual fluid volume of the blood processing circuit. In one embodiment, a volume of replacement fluid is conveyed to the donor during the desired blood collection procedure, and the estimated effect takes into account the volume of replacement fluid conveyed to the donor. In one embodiment, the estimated effect expresses the net blood fluid volume loss as a percentage of a blood volume of the donor that existed prior to the desired blood processing procedure. In one embodiment, the estimated effect expresses the net blood fluid volume loss as a percentage of weight of the donor.
According to another aspect of the invention, the estimated effect is expressed in terms of a hematocrit of the donor after completion of the desired blood collection procedure.
According to either aspect of the invention, blood can be conveyed through the blood processing circuit to collect a volume of red blood cells, or a volume of platelets, a volume of plasma, or combinations thereof. In one embodiment, in a first mode, platelets are collected while returning red blood cells to the donor and, in a second mode, platelets and red blood cells are collected without returning platelets or red blood cells to the donor.
According to either aspect of the invention, the estimated effect can be presented in a visual display, or in printed form, or in a data form suitable for offloading, or combinations thereof.
The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims. The invention is not limited to the details of the construction and the arrangements of parts set forth in the following description or shown in the drawings. The invention can be practiced in other embodiments and in various other ways. The terminology and phrases are used for description and should not be regarded as limiting.